Nooo. The stock valves will float on the O-200 at those RPM's, and you will not get anything useful out of it. The IF1 rules specifically do not allow different springs or lighter valves. I got 4200-4300 out of my O-200, built by a good race engine builder (Randy Musser, a former Lycoming QC inspector and race builder). Alan Preston once told me he managed to get 4400 out of Judy/Sitting Duck at high density altitude in Reno once, but I never heard that anybody got over 4500. Jim Miller had run a smaller prop when he was running that ducted fan in Pushy Cat, and didn't g et anything useful out of trying to turn it faster.BTW, those Formula One 200 CI Reno racers kick out around 150 HP at 4,500 - 5,000 RPM and only last for about 10 minutes.
And I'd like to add: easiness of construction?I know what you might be thinking, "This guy is asking about efficiency", and I suppose I am, but I'm not curious about MPG. MPG conversations always end up with Gliders or PPG's, and that's not what I'm after.
I'm more curious if anyone knows the fastest aircraft that have <80hp, <100hp, <150hp? The Reno Air Races seem like a good starting point, but then I hear about things like the Tailwind, TL Stream, Facet Opal... heck, even the Varieze seems like it belongs in this class of aircraft. Efficiency and speed.